<template>
    <div class="list" ref="wrapper">
        <div>
            <div class="area">
                <div class="title border-topbottom">当前城市</div>
                <div class="buttton-list">
                    <div class="button-wrapper">
                        <div class="button">{{ this.currentCity }}</div>
                    </div>
                </div>
            </div>
            <div class="area">
                <div class="title border-topbottom">热门城市</div>
                <div class="buttton-list">
                    <div class="button-wrapper" v-for="item of hotCities" :key="item.id" @click="handleCityChange(item.name)">
                        <div class="button">{{ item.name }}</div>
                    </div>
                </div>
            </div>
            <div class="area" v-for="(city, key) of cities" :key="key" :ref="key">
                <div class="title border-topbottom">{{ key }}</div>
                <div class="item-list">
                    <div class="item border-bottom" v-for="item of city" :key="item.id" @click="handleCityChange(item.name)">{{ item.name }}</div>
                </div>
            </div>
        </div>
    </div>
</template>

<script>
//引入第三方滚动插件 cnpm install better-scroll --save
import BScroll from 'better-scroll'
import { mapState, mapMutations } from 'vuex'

export default {
    name: 'CityList',
    props: {
        hotCities: Array,
        cities: Object,
        letter: String
    },
    methods: {
        handleCityChange(city){
            // this.$store.commit('changeCity',city)
            this.changeCity(city)
            this.$router.push('/')
        },
        ...mapMutations({
            changeCity: 'changeCity'
        })
    },
    computed: {
        ...mapState({
            currentCity : 'city'
        }) //映射vuex公用属性city  ---展开运算符...
    },
    mounted(){  //页面挂载完毕之后自动执行
        this.scroll = new BScroll(this.$refs.wrapper)
    },
    watch: {  //监听leeter是否改变
        letter(){
            if(this.letter){
                const element = this.$refs[this.letter][0]
                this.scroll.scrollToElement(element)
            }
        }
    }
}
</script>

<style lang="stylus" scoped>
    @import '~styles/varibles.styl'

    .border-bottom
        &:before
            border-color #ccc

    .list
        position absolute
        top 1.58rem
        left 0
        right 0
        bottom 0
        overflow hidden
        .title
            line-height .54rem
            background #eeeeee
            padding-left .2rem
            color #666
            font-size .26rem
        .buttton-list
            overflow hidden
            padding .1rem .6rem .1rem .1rem
            .button-wrapper
                float left
                width 33.33% 
                .button
                    margin .1rem
                    padding .1rem 0
                    text-align center
                    color #333
                    border .02rem solid #cccccc
                    border-radius .06rem
        .item-list
            .item 
                line-height .76rem
                padding-left .2rem
                color #333

</style>


